Arc-flash is the result of a rapid release of energy due to an arcing fault between a phase bus plate and another phase bus plate, a neutral or a ground.
During an arc fault, the air is the conductor that creates an arc similar to an arc obtained during electric welding. The arc fault is typically manually started by a failure along the path of conduction, such as a breakdown in insulation.
The cause of the short often burns away during the initial flash. The arc flash is then sustained by the establishment of highly conductive plasma around the fault.
The plasma will conduct as much energy as is available limited only by the impedance of the arc. This massive energy discharge burns the bus plates, vaporizes the copper and causes an explosive volumetric increase. The arc blast, conservatively estimated, has an expansion of 400,000 to 1. This fiery explosion devastates everything in its path creating deadly shrapnel as it dissipates.
Several incidents have occurred in recent years which have resulted in injury and death due to these arc blasts.
The majority of arc blast incidents occurred while a circuit breaker was being installed or removed from a circuit breaker cabinet. Since removing and installing circuit breakers requires a user to be in close proximity to switchgear being installed, and on some occasions to be physically in the circuit breaker cabinet itself, it is a highly hazardous activity and a need has existed for this activity to be done by remote control or by a remotely controlled robot or similar tool.
A need has existed for a specialty installation tool designed for safety and reliability protecting a user from the deadly arc blast.
A further need exists for an attachment for, or component of, the specialty installation tool for actuating interlocks, handles, or levers required for engaging and disengaging circuit breakers from their circuit breaker cabinets. A common interlock found in circuit breakers is a foot lever interlock. Ordinarily, this interlock requires an operator to manually push the lever with their foot while they pull the circuit breaker out of the circuit breaker cabinet. Therefore, a need exists for a device to remotely actuate interlocking levers and pull the circuit breakers out of the circuit breaker cabinet for operator safety.
A further need exists for an attachment for, or component of, the specialty installation tool for securing the tool to the cabinet to help establish the relative motion between the circuit breaker and the circuit breaker cabinet.
The present embodiments meet these safety and reliability needs, prevents death, destruction and explosions for a user with a remotely operated vehicle that can install or remove circuit breakers from a cell of a circuit breaker cabinet.
The present embodiments are detailed below with reference to the listed Figures.